On my 757 the gear is visible and all other gauges are working as well.  Where the fmc is located is a brown square..  My 707 is missing landing gear only and my 727 windows come open and won't close unless I'm outside looking in.  But once I get back into the cockpit they open again..  I have fsx acceleration...  I guess I'll give that a shot and reinstall fsx acc.  That's for the suggestion!!